wagtail_bakerydemo/bakerydemo/templates/blocks/heading_block.html

{% if self.size == 'h2' %}
	    <h2>{{ self.heading_text }}</h2>

	{% elif self.size == 'h3' %}
	    <h3>{{ self.heading_text }}</h3>

	{% elif self.size == 'h4' %}
	    <h4>{{ self.heading_text }}</h4>

{% endif %}

{% comment %}
	Content is coming from the StandardBlock StreamField
	class within `blocks.py`
{% endcomment %}